1. Technical Field
The invention refers to a device for measuring angles, in particular for measuring angles that occur when bending sheet metal and similar material by means of press brakes and other bending devices.
2. Description of the Prior Art
It is known to arrange a displaceable feeler pin at the die of a press brake in the direction of pressing where the feeler pin affects an electronic position detector as the sheet is bent so that a value of the angle of bending is obtained.
A device is known from EP 0 594 532 where a plate mounted for rotation with a detecting edge positioned along a chord is turned under the influence of a sheet bent against a die whereby the rotated position gives the degree of bending. A common factor of known detectors of the latter type is that the rotating element, plates and similar, must have a defined axis that is positioned in a specified relation to the radius over which the bending takes place in order for a secure measurement to be obtained. With other types of devices, one has tried to solve this problem by ensuring good contact fit by allowing some kind of spring mechanism to press the actual detector against the piece being worked. In addition to these known devices often giving an uncertain result, they can only be used together with a specific die set, which means that one is forced to stock an angle measuring mechanism for each die set.